4-Methylpyridine → Dimethyl-(2-pyridin-4-yl-vinyl)-amine

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Reaction Steps

A solution of 4-methylpyridine (3.7 g, 40 mmol) and bis(dimethylamino)-tert-butoxymethane (8.44 g, 48 mmol) in DMF (10 mL) was heated at reflux for 12 hours under a nitrogen atmosphere and then concentrated under vacuum to give a tan solid. The product was re-crystallized from cyclohexane to give compound 4-(2-dimethylaminovinyl)pyridine (5.0 g, yield 85%) as light yellow crystals. A solution of 4-(2-dimethylaminovinyl)pyridine (5.0 g, 33.8 mmol), ethyl cyanoacetate (3.8 g, 33.8 mmol), sulfur (8.6 g, 270.2 mmol) and morpholine (1 mL) in EtOH (50 mL) was heated at 80° C. under a nitrogen atmosphere for 3 hours and chilled in ice. The resulting crystals were collected by filtration, washed with hexane, and dried to give the title compound (5.5 g, 66% yield) as an orange solid:

Provenance & Evidence